This invention relates to intrusion detection systems and more particularly to a control circuit for use with such a system.
As is known, burglar alarms, fire alarms or detection systems in general have found widespread use and hence, the prior art is replete with many types of such systems.
Essentially, the systems are operative to detect an intrusion on a premises which is monitored and to sound an alarm or provide an indication when an unauthorized intrusion occurs. It is understood that the term "intrusion" is used in its generic sense and hence such an intrusion may indicate the presence of a burglar, fire, or some other undesired condition on the premises or location which is being monitored by the intrusion system.
As is conventional, such systems are placed into operation when the premises are secured as after working hours or during a period of closing as a vacation and so on. Hence, in order to place the system in an operating mode, one usually activates a switch or other device to energize the system. The switch may be operated from a location remote from the premises to be secured or operated on the premises. If the system is activated on the premises, the system usually employs a time delay or a disabling mode to enable the operator to leave the premises through a door exit which is monitored by the system. Hence, his leaving if not for a time delay or other inhibiting device, could undesirably trigger or operate the system.
The prior art therefore has a plurality of techniques for enabling one to activate a system on the premises to thereafter exit without triggering the intrusion alarm or the intrusion mode. Many such devices are complicated, require additional circuits and other components and hence, serve to increase both the complexity and cost of such systems.
It is therefore an object of the present invention to provide an improved control circuit for use with an intrusion system to enable exit delay while further providing an automatic setting feature to enable reliable operation while further reducing the complexity and cost of such systems.